Multiple 8x8 LED Matrix Control with MAX7219 — Parallax Forums
How to control 4 digit 7 segment display with MAX7219 module - YouTube
Amazon.com: AITRIP 5 PCS 8 Digit 7 Segment Module MAX7219 8 Bit Digital Segment Tube LED Display Module Compatible with Arduino MCU/51/AVR/STM32/Raspberry Pi 4 Model B : Industrial & Scientific